RESUMEN
In a prospective study of 3000 consecutive deliveries (14 twin deliveries), the rate of congenital malformation was reported to be 27.20 per 1000 births (82 out of 3014). No significant difference was observed in the frequency of congenital malformation in urban rural status, in different religion and caste, and in male female babies. An increase in frequency was seen in advanced maternal age and in primi and fourth gravida mothers. A number of environmental factors studied, such as use of different tooth powders, type of drinking water, different cooking vessels, associated vitamin deficiencies did not seem to influence the prevalence of birth defects significantly. The factors which significantly increased the rate of congenital malformation were consanguinity in parents, heredofamilial history of malformations, presence of hydramnios, maternal febrile illness in first trimester, past history of abortion and history of progesterone intake during pregnancy.